The concept of the folding wing hand launch glider was devised in an attempt to overcome the problems associated with launching small gliders. The gliders have to be kept as light in weight as possible to fly well, but designers have found that by building the planes stronger and thus heavier they were able to launch the planes with a greater force which gave the plane more altitude and oftentimes longer flights.
When a conventional fixed wing hand launch glider is thrown hard in an attempt to gain more altitude from the launch, the wings produce much more lift than the plane needs. Since the lift of a wing increases to the square of the velocity, increased velocity at launch means more lift which tends to cause the glider to loop in the air. To keep the glider on the desired launch path, the elevator must be applied downwardly to counteract the extra lift of the wing. The resulting configuration of the flying surfaces produces a large amount of drag which slows the aircraft and wastes a large amount of the kenetic energy transferred to the plane during the launch. Not only is extra drag produced, but the wings are stressed much more than normal. In order for the wings to survive such stressful launches they have to be made stronger which in turn means the gliders are going to be heavier.
There is a definite need for a lightweight hand launch glider having reduced drag during launch and also having the capability of being launched with great force without causing unwanted looping.